This invention relates to the introduction of crankcase gases and recirculated exhaust gases into the intake system of an internal combustion engine. It has been determined that the combination of crankcase gases from a positive crankcase ventilation system ("PCV") with recirculated exhaust gases from an exhaust gas recirculation ("EGR") system will result in the formation of carbonaceous sludge-like material if the PCV and EGR flows are combined at or near a throttle body positioned well upstream from intake ports extending through the cylinder head. The present invention prevents this sludging problem by combining the EGR and PCV flows only in the intake port. In this manner, the EGR and PCV combined flow will have little residence time either outside or inside the combustion chamber, and in the likely event that mixing between the PCV and EGR flows occurs in the intake port, the formation of sludge or carbonaceous material will be greatly reduced, if not eliminated entirely. Although it is known to introduce EGR flow upstream of the cylinder head ports through the use of a spacer introduced between the intake manifold and cylinder head, such a system requires additional components and provides additional potential vacuum leak paths. The present system, by introducing EGR and PCV gases directly into the intake ports of an engine, serves to prevent the buildup of induction-borne sludge, without creating the potential vacuum leak paths found with the systems of the prior art.